In the past many wound dressings included an absorbent material and an adhesive to secure the dressing to the wound. The adhesive portion allows the absorbent material to stay substantially in contact with the wound by adhering to the region of the body surrounding the wound, typically the skin. The adhesive portion however needs to be strong enough to secure the dressing to the wound for an extended period of time, yet still release from the skin after use. These adhesives however can have a traumatizing effect when the dressing is removed. As the dressing is removed, the force required to separate the adhesive from the skin may cause pain and discomfort to the dressing wearer as the skin and hair are subjected to yanking or pulling and stretching.
Some wound dressings apply a trauma reduced adhesive, such as a silicone based adhesive, to reduce the trauma associated with the release of the dressing from the wound site. For example, the characteristics of polymerized siloxanes such as silicone gels allow the dressing to remain secured to the wound region yet require less pull force to remove the dressing resulting in reduce trauma during the release. Some wound dressings have a silicone gel covering the entire dressing including the wound contact portion to secure the absorbent material to the wound. However, silicone adhesives on dressings when in a continuous layer provide very low moisture vapor transmission rate (MVTR) of the dressing. This leads to increased perspiration, poor breathability of the wound and as a result increased healing time. The dressing needs to remain on the wound as long as possible to reduce infection yet be breathable enough to prevent or reduce skin maceration also leaving the wound more vulnerable to infection. One method incorporated into current dressings to improve the MVTR is to discontinuously or selectively apply the silicone based adhesive to the dressing in one fashion or another. In one application the silicone adhesive is applied to the foam so as to contact the wound.
However, covering the wound contact portion of the dressing with silicone reduces the absorbency rate of the dressing. This leads to a slower rate of absorption over time, increasing the chances of maceration in the peri wound area.
Applying the silicone adhesive to the backing and then securing a foam pad to the backing with the silicone, as with a typical “island” type dressing, results in poor adhesion of the foam to the backing. This is particularly the case once the foam becomes wet and the adhesion characteristics of the silicone to the foam is reduced and the foam separates from the backing.
Some dressings incorporate a superabsorbent material to increase the amount of fluid retainable by the dressing thereby decreasing the amount in the wound and thus improving the healing ability of the dressing. This may further reduce the number of dressing changes and potentially reducing dressing change trauma, plus infection of the wound as with each dressing change and exposure to the environment, chances of infection increase.
Further, absorbent material, and more particularly super absorbent material, can be unpleasant feeling to the user when put in direct contact with the skin, particularly for long periods of time and even more so once the absorbent material becomes wet.
Another problem is that absorbent/SAP materials, which usually consist of superabsorbent particles bonded to a carrier layer, tend to swell exuberantly, in particular the superabsorbent particles loosen from the carrier as they fill with exudates being expressed by the wound.
Thus, there is a need for a non traumatizing wound dressing that has a large super absorbent area with high MVTR at the wound contact region and that maintains its structure when wet.
The various aspects, features and advantages of the disclosure will become more fully apparent to those having ordinary skill in the art upon careful consideration of the following Detailed Description thereof with the accompanying drawings described below.